Safety pilot light



Dec. 24, 1940. J. T. HUNTINGTON 2,225,743

SAFETY PILOT LIGHT Filed Oct; 21, 1939 2 Sheets-Sheet 2 J T Hurrf/nyfwz Qzttowwn Patented Dec. 24, 1940 UNITED STATES PATENT OFFICE 2 Claims.

This invention relates to safety pilot lights, and the operating and related devices associated and combined therewith for preventing the escape of unburned gas fuel it from any cause the flame at the burner should be extinguished.

The invention has for its object the special construction and arrangement of members for controlling the valve by way of which the gas is admitted to the main burner, but it is not intended to limit the invention to the exact formation and disposition of the remaining details employed.

Drawings accompanying this specification illustrate the invention, and Fig. 1 of the drawings sets out a water heater, partly in section at its lower portion, to which this invention is shown applied.

Fig. 2 is a top or plan view on a larger scale of drawing showing the valve casing and parts supported and carried by the casing.

Fig. 3 is a vertical sectional view of this invention showing all parts as usually arranged.

Fig. 4 is a side View of the end pf the pilot light tube.

Fig. 5 represents a side view partly in section showing a modified arrangement of the parts of this invention.

Fig. 6 is a top or plan view of the parts shown in Fig. 5.

Fig. 7 is a side View of the valve at the end of the valve stem or rod, showing the movable sleeve on the valve stem, also the slot in the Valve stem with the pin carried by the push rod in the slot for moving the sleeve.

Throughout the drawings and description the same number is used to refer to the same part.

Considering Figs. 1 to 4 of the drawings, a water heater of any chosen form and extent, has the customary internal water container 2 with an outlet 3 for the heated water. It will be understood that a suitable water connection is arranged to furnish water to the container. A

gas burner 4 applies the heat and the products of combustion may be discharged at the top outlet 5. A fuel serving pipe 6 to the main burner 4 is provided with an air admitting connection I to produce the customary mixture of gas and air. A pipe 8 connects the serving pipes with a valve casing 9 to which leads the gas supply pipe H). In

Fig. 3 it is shown that the casing 9 has two cham-- bers H and i2, and the wall between the chambers is pierced by an opening constituting a valve seat i3. Opposite the seat in the outer wall of the casing is a threaded cylinder |4 having the hexagonal nut head |5 and affording a fitting bore for the push rod l6 outwardly held by the encircling spring I! and operable by hand by the head l8- A valve IS in the casing is normally pressed towards its closed position upon the said seat by a coil spring 20 encircling the cylindrical 5 stem 2| of the valve within the casing. The stem passes through the stuifing box 22 to the outside of the casing and slides back and forth in a suitable guiding cavity 23 formed in a branch or extension 24 of the extension which is removable 10 from the casing asshown.

In Fig. 3 appears a longitudinally movable rod 25, the function of which is to rock a member 26 termed for the purposes of this explanation a clutch plate. The lower end of the plate is piv- 15 otally held in a socket 21 in the extension 24' of the casing, and the rod passes through an opening 28 in the upper port of the plate 26 and terminates in a head 29. Clearly, a movement lengthwise of the rod. to the right will rock the 20 plate in like direction. Upwardly at the outer end of extension 24 is an integral block portion 30' in which is held one end of a pipe 3| through which the rod 25 passes. At the remaining end the pipe 3| carries the twin nuts 32 and 33 the 25 oflice of which is to clamp in place the U-shaped bimetal strip 34, the other end of the strip 34 bears against the head 35 terminating the rod 25 at its left hand end. If the operating rod 25 moves to the left it brings the plate 26 into a ver- 30 tical position and permits the spring 20 to close valve l9. But if the rod moves the opposite direction, to the right, it allows the spring 39 to incline plate 26 and clutch or clamp the valve stem 2| in opening 26' all as indicated in Fig. 3. In Figs. 3 35 and 4 are illustrated the connection 36 to the pilot light tube 31 having the usual gas slot 38 and constituting the pilot light burner of. this form of the invention.

Considering Figs. 5, 6 and 7, a modification of 40 this invention will be observed. The valve 4|], stem 4| and the encircling closing spring 42 are substantially the same as the like parts previously described. The stuffing box 43 is now in an extension 44 of the casing of modified formation. 45 The extension is hollow as shown and contains a movable sleeve 45 that slidably fits in the hollow of the extension. The stem 4| has a longitudinal bore 46, and movably inserted in the bore is the operating rod 41. The stem 4| has also the slot 50 48 extending for a distance and passing through the stem, and the rod 41 has a pin 49 passing through it and engaging the slot 48. The pin 49 is adapted to be brought into contact with the right hand end of the movable sleeve 45, and if 55 the rod 47 is moved to the left the sleeve will displace the balls 50 and 50' from contact with the inclined ball race 5| and at the same time compress the spring 52. This action will free the stem 4| and permit the spring 42 to close the valve 40. If, however, the rod 41 moves toward the right hand side, the spring 52 presses upon the plate 5! and forces the balls into contact with the inclined race thereby clamping the stem 4| and holdingthe valve 40 in the open position to which it has been moved by means of the hand operated rod I 6. Rod 4! passes through the pipe 53 carried by the extension of the casing, and the nuts 54 and 55 on the left hand end of the pipe secure one end of the bimetal contraction and expansion strip 56. contact with the head nut 51 on the end of the rod 41. Pilot light tube 58 has the gas serving connection 59. v

The operation in both the form first explained and in the modified form is the same. The heat of the pilot light burner contracts the U-s'haped strips, but if the pilot light is by any cause extinguished the strips expands and the springs arranged next to the valves close the valves, which must beagain opened by hand to the adjustment desired. The forms of this invention herein illustrated and described have been found to be particularly reliable in use, and the the apparatus does not get out of order or become. disarranged by continued service.

Having now described this invention, 1 claim:

1. In apparatus of the characterdescribed, in combination, a gas burner, a fuel serving pipe connected with the burner, a valve casing having two chambers, one of said chambers being connected with said fuel serving pipe, a wall between The end of the strip'is in the chambers having a valve seat, a valve, a cylindrical stem for the valve, a spring operable to close the valve upon the seat, a clutch plate supported in a rocking position and provided with an opening, said valve stem passing through the opening, a spring arranged to rock the plate and clutch said valve stem, a pilot light, heat expansible means adjacent to the light, and devices movable by said eXpansible means and constructed and arranged toact upon said plate whereby the plateis inclined to clutch the valve stem and erected to release the stem, and hand operated devices carried by the casing for opening the valve.

' 2. In apparatus of the character described, in combination, a gas burner, a fuel serving pipe connected with the burner, a valve casing having a valve seat, a valve arranged to open and close the seat, hand operated devices carried by the casing for opening the valve, said valve having a stem extending from the casing, an extension of the casing constructed and arranged to guide the valve stem, a rocking clutch plate having an opening, the valve stem passing through the opening, a rod supported by the said extension of the casing and arranged to be reciprocated lengthwise, said rod being connected with the said clutch plate, a pilot light, expansible devices arranged adjacent to the light and adapted to move the rod, means in conjunction with the rod and arranged to act upon the clutch plate whereby the movements of the rod rocks the clutch plate to clutch the valve stem and erects the plate to release the stem and permit the valve to close.

J. T. HUNTINGTON. 

